This invention relates to valves and suction catheter assemblies.
Closed system suction catheter assemblies are used to remove secretions from within a tracheal tube or the respiratory passages of a patient. The assembly comprises a manifold at one end with a sliding seal through which a suction catheter can be advanced and withdrawn. A flexible envelope is joined at one end to the manifold and encloses the catheter along its length. The other end of the envelope and the catheter are joined with a rear end component including a suction control valve and a connector. The connector connects the catheter to a suction source and the valve enables the clinician to control the suction applied by the catheter.
Suction catheter assemblies are disposable, single-patient items so it is important that their cost is low. The cost of the valve contributes a significant part to the overall cost of the assembly so it is important that this can be made at low cost whilst also operating efficiently with low risk of blockage and leakage. Various forms of suction control valves have been described previously such as in U.S. Pat. No. 5,269,768, U.S. Pat. No. 5,300,043, U.S. Pat. No. 4,569,344, U.S. Pat. No. 4,638,539, U.S. Pat. No. 4,836,199, U.S. Pat. No. 4,872,579, U.S. Pat. No. 5,277,177 and U.S. Pat. No. 5,215,522. There are also applications other than closed system suction catheters where similar forms of valves are required.